Temperature measurement error reduction for MRI-guided HIFU treatment

Area of Science:

• Medical Physics
• Biomedical Engineering
• Radiology

Background:

• MR thermometry using proton resonance frequency (PRF) shift offers accurate temperature imaging for MR-guided high-intensity focused ultrasound (MRgHIFU) tumor treatments.
• Ultrasound applicator movement during MRgHIFU causes magnetic susceptibility artifacts, leading to temperature measurement errors.
• Conventional methods require repetitive reference scans and cooling periods, complicating and prolonging the treatment workflow.

Purpose of the Study:

• To develop and present a method for reducing temperature measurement errors caused by ultrasound applicator movement in MRgHIFU treatments.
• To improve the accuracy and efficiency of MR thermometry during MRgHIFU procedures.

Main Methods:

• Proposed a novel method to compensate for magnetic susceptibility artifacts induced by the ultrasound applicator.
• Utilized pre-measured or calculated magnetic field distribution of the applicator for error correction.
• Enabled repositioning of the applicator without acquiring new reference images.

Main Results:

• Significantly reduced temperature measurement errors around the ultrasound focal region by compensating for applicator-induced magnetic fields.
• Achieved accurate temperature maps after applicator repositioning without the need for repeated reference scans.
• Demonstrated the feasibility of using a single reference image throughout the treatment.

Conclusions:

• The proposed compensation method effectively minimizes temperature measurement errors during MRgHIFU.
• Repetitive use of a single reference image simplifies the treatment workflow and reduces overall treatment time.
• Enhanced accuracy and efficiency in MRgHIFU treatments through improved MR thermometry.